package lengthOfLongestSubstring;

import java.util.HashSet;
import java.util.Set;

public class Solution {
    public static int lengthOfLongestSubstring(String s){
        Set<Character> occ = new HashSet<Character>();

        int n = s.length();
        int rk = -1, ans = 0;
        for (int i = 0; i < n; i++){
            if (i != 0) occ.remove(s.charAt(i - 1));
            while (rk + 1 < n && !occ.contains(s.charAt(rk + 1))){
                occ.add(s.charAt(rk + 1));
                rk++;
            }
            ans = Math.max(ans, rk - i + 1);
        }
        return ans;
    }
}
